Friday, June 29, 2007

Two new videos highlight changing universe

How did the universe get its structure? It was very smooth when it was born, with matter distributed incredibly evenly through space. Now, thanks to the action of gravity over billions of years, it is very lumpy, with dense clusters of galaxies separated by enormous voids.

Unlike previous simulations, Di Matteo's team included black holes in their simulation. The black holes are not highlighted in the animation, but they do influence their surroundings.

Increasingly, scientists are realising that supermassive black holes weighing millions or billions of times the mass of the Sun may affect their environment more than previously thought. Their enormous gravity can capture and swallow vast quantities of matter from their immediate vicinity, but they can also produce jets and radiation that can influence matter much farther away.

Another cool animation released recently shows the effects of the solar wind on Earth's magnetosphere. The solar wind constantly buffets the magnetosphere, stretching and bending magnetic field lines until they suddenly snap in what are called magnetic reconnection events.

ESA's four Cluster spacecraft have been investigating this phenomenon and ESA recently put out an animation illustrating this magnetic field snapping.

I'm fascinated by how a combination of science and computer graphics can show you things that you could never witness firsthand – like cosmic changes that unfold over billions of years in the case of Di Matteo's simulation, and the normally invisible dance of magnetic field lines in the case of the Cluster animation.